Project Summary/Abstract For the last four decades, the Gordon Research Conference on Developmental Biology has brought together ~150 outstanding senior and junior scientists for discussions of the recent advances in the field, and is recognized as the major and most prestigious mid-size meeting in Developmental Biology. The conference has several features that make it unique. It spans a wide variety of experimental systems and focuses on areas of exceptional activity or promise. This broad view and comparative analyses helps to define the truly essential underlying mechanisms. In 2019, 29 invited speakers, chosen based on their creative contributions to the field the field and their ability to promote fruitful discussions, have confirmed their attendance. Nearly half (14) of the invited speakers are women, two are underrepresented minorities, and we have made substantial efforts to encourage and recruit participation from a diverse population of scientists. Topics for this year include: Cell identity and robustness in the era of single-cell 'omics, Developmental time, Towards in vitro precision in vivo, Chromatin and epigenetic influences on cell identity, Dynamic imaging (and imaging dynamics), New concepts of pattern, Metabolism and growth control, and Developmental robustness in noisy systems. This year we will also pay tribute to 50 years of ?Positional Information?, recognizing the 1969 landmark paper by Lewis Wolpert and the work by Wolpert and others that led to this conceptual synthesis. For each session, time has been kept uncommitted to choose speakers from abstracts submitted by the participants. All participants will be given the opportunity to present their work in poster sessions. By maximizing both formal discussion and informal interactions, the Gordon Conference on Developmental Biology will help to define both the present state and the future of the field.